There is an ever increasing need for new biomaterials for the repair, replacement, construction or augmentation of hard and soft tissues in response to degenerative diseases, other diseases and conditions, trauma and cosmetic treatments. In particular, there is a need for biomaterials which are bioactive, and may be biodegradable, and possess appropriate mechanical and physical properties for a specific application. Depending on the application, biomaterials which are injectable or those with three-dimensional porous structures (i.e. scaffolds) for inducing cell invasion, attachment and proliferation may be required.
Biomaterials based on hydrogels are known. For example, collagenous hydrogels, such as type I collagen, have excellent biological behaviour, can form physiologically relevant scaffolds and can be injectable. However, collagenous materials have low strength and are therefore unsuitable for many applications. Also, most collagenous materials are rapidly and unpredictably reabsorbed by the body when implanted and also undergo significant cell contraction under physiological conditions.
Biomaterials based on mineralized collagen are particularly attractive for the repair, replacement, construction or augmentation of hard tissues, e.g., bone, as collagen forms the organic component of bone. Existing methods for mineralizing collagen require the processing of the collagen under conditions outside of physiological conditions in terms of pH, temperature, and high concentrations of minerals. As these mineralizing conditions cannot be recreated in the body, collagen must be mineralized before implantation and must therefore be implanted. These materials are also unable to support live cells during mineralization. An injectable mineralizable biomaterial based on collagen does not exist. Like unmineralized collagen, mineralized collagen also suffers from unpredictable reabsorption properties, and cell induced contraction.
Therefore, it is desired to provide an improved biomaterial, and method for making the biomaterial, for tissue construction, repair, replacement or augmentation in order to overcome or reduce at least some of the above described problems.